I. Field of the Invention
The present invention relates to checkout systems and more particularly to a system allowing the customer to check out the purchased items.
II. Description of the Prior Art
In a merchandise checkout operation, an operator will move the purchased merchandise items past an optical scanner which scans a coded label on the purchased item and outputs electrical signals identifying the item. When the item is required to be weighed, the operator places the purchased item on a scale which weighs the item and generates signals representing the weight used in determining the price of the item. The operator then enters the price of the item into a data terminal device which prints the necessary data on a receipt which is then given to the customer after the customer has paid for the purchased items. The cost of the individual purchased items and the total cost of the items are displayed to the customer on a display associated with the terminal device. This operation of checking the purchased merchandise items is very costly in terms of using such a checkout operation in each checkout lane, in addition to being a relatively slow operation when a large number of merchandise items are being purchased. In order to overcome these drawbacks in the use of such a checkout system, self-service checkout systems have been proposed. In one system, the customer places an empty grocery cart on a scale and scans each purchased merchandise item by moving the item past a scanning mechanism. As each purchased item is scanned, a computer records its weight and price and generates a first combined weight of the items scanned. At the end of scanning each item, the customer places the item in the empty cart. The scale on which the cart is positioned generates a second combined weight which is used to verify that the accumulated weight of the items in the cart matches the combined weight of the individual purchased items scanned. The customer then takes his purchased items to a cashier who will complete the checkout operation only when there is a match between the first and second combined weight data. The disadvantage of this system is that items having the same weight but different values can be interchanged prior to the final checkout operation.